Cloudy water after heavy rain and runoff into pool

by Robert S
(Knoxville TN)

First let me thank you for your wonderful informative website. Only wish I had come across it sooner. We had an extreme rain event that introduced dirty (gravel dust and dirt) into our pool as well as the rainwater rose about 3-4 inches and was half way up the coping.

I came out the next morning and our water had went from crystal clear (which it has been all along this season) to almost a milky cloudy nastiness.
We have an approximately 14,500 gallon fiberglass pool with Hayward cartridge filter and PureChlor salt system. The only thing I have done to it prior to this was skim daily, vacuum weekly and spray the filter out weekly. I only added salt because the light lit up telling me to add salt.

I had not had the water tested one time.
Anyhow, after this rain event and the cloudiness I drained down the water and vacuumed, cleaned filter and let the system run overnight to no change.
I then went to Leslie's pool supply and they suggested their clarifier (which I've learned now from watching your video I shouldn't have probably used).

I also added about 40 pounds of salt and have been running the system non stop on super chlorinate for about 24 hours now. You can see the bottom of the pool now but it is still cloudy.

Here are the numbers prior to adding salt and the clarifier
Free Chlorine 1.5
Total available chlorine 1.5
Alkalinity 80
Hardness 60
And as mentioned I have a cartridge filter

What should I do next sir?

Hi Robert. It seems like you situation is very easy to solve. Turn off your cell. You're not going to need it for this process. First is to increase the CYA to 30 - 50 ppm using either granular or liquid.The FC is not holding well and this should solve it.

Clean the filter out and add in 2.5 gallons of liquid chlorine. Pour around the perimeter of the deep end and sweep after each gallon is added. This will increase the FC up to 15 ppm. The FC will decrease so you might end up adding another gallon to bump it back up. Keep filtering, maintain the FC AM and PM that high and clean the cartridge every 24 hours until the water clears. That should take care of it. Once the water clears you can allow the FC to decrease to its normal level.

Clarifiers are alright but really not needed for weekly maintenance. And never use a floc with a cartridge filter. That's only for sand and DE filters with a multiport valve.

Good luck and have a great rest of the Summer.


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Sep 03, 2017
Leak in sand filter
by: Kevin

I noticed a crack in top part of sand filter. Water is leaking out. Sparco sand filter is 11 years old. I noticed towards end of season and decided to address the problem next year, as I was told I need a new filter. Do not attempt to fix leak I was told. Gage reads a little higher than normal and pressure of return is very low! On top of all this, we have battled algae problems almost all year and most of last year. Could this be due to problem with pump? I'm thinking so. Never experienced this before last year. Very frustrating!

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